High Temperature Oil

ABSTRACT

The invention relates to novel high temperature oils based on aromatic esters, such as trimellitic acid esters, pryomellitic acid esters, trimesic acid esters or a mixture thereof or derivatives of phloroglucinol and a fully hydrated or a hydrated polyisobutylene or a mixture thereof.

The invention relates to novel high-temperature oils based on aromaticesters such as trimellitic esters, pyromellitic esters, trimesic estersor a mixture, or derivatives of phloroglucinol such as phloroglucinoltrioctanoate, phloroglucinol tridecanoate and phloroglucinoltridodecanoate thereof, and a fully hydrogenated or a hydrogenatedpolyisobutylene or a mixture thereof.

High-temperature oils which are used in the field of industrial chainlubrication, for example in conveying systems, painting lines, thetextile industry, the insulating materials industry, the glass industry,etc., and belt lubrication in continuous wood pressing plants, typicallyconsist of a three-component system.

This three-component system generally consists of an aromatic ester, asynthetic hydrocarbon and a polymer based on polyisobutylene. Thesynthetic hydrocarbon is used as a solubilizer. Also added to thislubricant system are commercial additives. However, a disadvantage ofthese systems is that the use of the synthetic hydrocarbon limits theworking temperature of the oil, since it vaporizes very rapidly attemperatures >200° C.

A three-component system is described, for example, in EP 1 154 011 B1.Here, a lubricant oil composition comprising an aromatic ester compoundand, as a further base oil, an α-olefin oligomer, and also apolyisobutene, is provided.

As already stated above, the loss of performance for a three-componentlubricant composition is high as a result of the vaporization of thesolubilizer. The vaporization results in formation of a deposit or aresidue formed from the remaining constituents of the lubricant on theapplication surface or the application area, as a result of which fulllubrication can no longer be ensured. This deposit then has to bedissolved again. In general, operation has to be stopped and the residuehas to be removed. There is thus a need for a high-temperature oil inwhich the vaporization of individual constituents of the oil is greatlyreduced and hence the lubricity is not lost at constantly hightemperature over a long period.

Such a high-temperature oil is especially required for chain and beltlubrication of wood presses, as present, for example, in Contipressen™continuous presses for the production of laminate floors.

It was an object of the present invention to provide a high-temperatureoil with which good lubricity is achieved at constantly high temperatureover a long period and which can be provided in different viscositiesaccording to the application.

This object is surprisingly achieved by the provision of ahigh-temperature oil which consists, as a two-component system anaromatic ester of the general formula (I)

where R1 is a linear or branched alkyl group having 6 to 16 carbon atomsand n is 3 or 4, or a compound of the general formula (II)

where R is a linear or branched alkyl group having a chain length of 8to 16 carbon atoms and n is equal to 3,

and

a hydrogenated polyisobutylene, a fully hydrogenated polyisobutylene ora mixture of a fully hydrogenated and a hydrogenated polyisobutylene.Preferably, a fully hydrogenated polyisobutylene is included.

In general, the high-temperature oil comprises 40 to 91.9% by weight ofthe aromatic ester of the general formula (I) or of the compound of thegeneral formula (II) and 50 to 5% by weight of the hydrogenated, fullyhydrogenated polyisobutylene or of a mixture of hydrogenated and fullyhydrogenated polyisobutylene.

In addition, the high-temperature oil may comprise 0.1 to 6% by weight,especially 2 to 5% by weight, of an antioxidant.

The high-temperature oil may also comprise 0 to 4% by weight, especially0.3 to 3.5% by weight, of an antiwear agent, 0.1 to 1.0% by weight of ananticorrosive, and 0 to 2% by weight, especially 0.1 to 1.5% by weight,of an ionic liquid.

The ester compound of formula (I) present in the high-temperature oil ispreferably selected from the group consisting of esters of trimelliticacid, pyromellitic acid, trimesic acid or mixtures thereof. The compoundof the general formula (II) is a derivative of phloroglucinol(benzene-1,3,5-triol), preferably phloroglucinol trioctanoate,phloroglucinol tridecanoate and phloroglucinol tridodecanoate.

The antioxidant present in the high-temperature oil, which may containsulfur and/or nitrogen and/or phosphorus in the molecule, is selectedfrom the group consisting of aromatic aminic antioxidants such asalkylated phenyl-alpha-naphthylamine, dialkyldiphenylamine, stericallyhindered phenols such as butylhydroxytoluene (BHT), phenolicantioxidants having thioether groups, zinc dialkyldithiophosphates ormolybdenum dialkyldithiophosphates or tungsten dialkyldithiophosphates,and phosphites.

The antiwear agent present in the high-temperature oil is selected fromthe group consisting of antiwear additives based on diphenyl cresylphosphate, amine-neutralized phosphates, alkylated and nonalkylatedtriaryl phosphates, alkylated and nonalkylated triaryl thiophosphates,zinc dialkyldithiophosphates or molybdenum dialkyldithiophosphates ortungsten dialkyldithiophosphates, carbamates, thiocarbamates, zincdithiocarbamates or molybdenum dithiocarbamates or tungstendithiocarbamates, dimercaptothiadiazole, calcium sulfonates andbenzotriazole derivatives.

The anticorrosive present in the high-temperature oil is selected fromthe group consisting of additives based on “overbased” calciumsulfonates having a TBN of 100 to 300 mg KOH/g, amine-neutralizedphosphates, alkylated calcium naphthalenesulfonates, oxazolinederivatives, imidazole derivatives, succinic monoesters, N-alkylatedbenzotriazoles.

The ionic liquid (IL) used in the high-temperature oil comprises whatare called salt melts which, by definition, are liquid at temperaturesbelow 100° C. Many ionic liquids are also liquid at room temperature orat lower temperatures. Suitable cations for ionic liquids have beenfound to be a quaternary ammonium cation, a phosphonium cation, animidazolium cation, a pyridinium cation, a pyrazolium cation, anoxazolium cation, a pyrrolidinium cation, a guanidinium cation, amorpholinium cation or a triazolium cation, which may be combined withan anion selected from the group consisting of [PF₆]⁻, [BF₄]⁻,[CF₃CO₂]⁻, [CF₃SO₃]⁻. [(CF₃SO₂)₂N]⁻, [(R⁴SO₂) (R⁵SO₂)N]⁻, [(CF₃SO₂)(CF₃COO)N]⁻, [R⁴—SO₃]⁻, [R⁴—O—SO₃]⁻, [R⁴—COO]⁻, Cl⁻, Br⁻, [NO₃]⁻,[N(CN)₂]⁻, [HSO₄]⁻, or [R⁴R⁵PO₄]⁻, and the R⁴ and R⁵ radicals are eachindependently selected from hydrogen; linear or branched, saturated orunsaturated, aliphatic or alicyclic alkyl groups having 1 to 20 carbonatoms; heteroaryl groups, heteroaryl-C₁-C₆-alkyl groups having 3 to 8carbon atoms in the heteroaryl radical and at least one heteroatom fromN, O and S which may be substituted by at least one group selected fromC₁-C₆-alkyl groups and/or halogen atoms; aryl groups, aryl-C₁-C₆-alkylgroups having 5 to 12 carbon atoms in the aryl radical, which may besubstituted by at least one C₁-C₆-alkyl group, partly and fullyfluorinated alkyl radicals. However, further combinations are alsopossible. Anions of [PF_((6-x))R⁷ _(x)], [R⁷—SO₃]⁻ type are also known.R⁷ here represents partly or fully fluorinated radicals such aspentafluoroethyl or perfluorobutyl.

The following anion type is likewise quite thermally stable: (FSO₂)₂N.

In order to display positive action in oils, the ionic liquids shouldfirstly show solubility in the oils, although complete miscibility isnot absolutely necessary. The ionic liquids should be thermally stableand not promote corrosion, for example by forming reaction productswhich are noncorrosive or corrosive only in a very delayed manner in thepresence of water.

Particularly advantageous ionic liquids have been found to be those suchas tetraalkylammonium bis(trifluoromethylsulfonyl)imides andtetraalkylphosphonium bis(trifluoromethylsulfonyl)imides, for exampletrihexyl(tetradecyl)phosphonium bis(trifluoromethylsulfonyl)imide(HPDimide) and methyltrioctylammonium bis(trifluoromethylsulfonyl)imide(Moimide). Ionic liquids which have likewise been found to beparticularly advantageous are those such as tetraalkylammoniumtris(perfluoroethyl)trifluorophosphate and tetraalkylphosphoniumtris(perfluoroethyl)trifluorophosphate, for exampletetrabutylphosphonium tris(perfluoroethyl)trifluorophosphate (BuPPFET),trihexyl(tetradecyl) tris(perfluoroethyl)trifluorophosphate (HDPPFET).It has likewise been found that pyrrolidiniumtris(perfluoroethyl)trifluorophosphates are particularly advantageous.Also particularly advantageous are tetraalkylammoniumperfluorobutanesulfonates and tetraalkylphosphoniumperfluorobutanesulfonates such as trihexyl(tetradecyl)phosphoniumperfluorobutanesulfonate (HDPnonaflate).

It is also possible to use any desired mixtures of the ionic liquids.

The inventive two-component system has a much higher performance interms of thermal stability and residue formation or residuecharacteristics. The enormous rise in thermal stability is manifestedparticularly in a distinct increase in lubrication characteristics. Therelubrication intervals were extended and an energy saving of up to a30% power saving was achieved.

As already mentioned, the formation of residues is distinctly reduced.As a result, the formation of cracking residues is also reduced and theresidues formed can be very easily dissolved with fresh oil.

The appended figures show the advantages of the inventivehigh-temperature oil based on two components.

FIG. 1 shows the friction values as a function of temperature at a loadof 250 N for an inventive high-temperature oil based on two componentsfrom example 1 compared with a known oil based on three components fromcomparative example 1 at a kinematic viscosity at 40° C. of about 260mm²/sec;

FIG. 2 shows the vaporization losses for an inventive high-temperatureoil based on two components from example 1 compared with a known oilbased on three components from comparative example 1 at a kinematic baseoil viscosity at 40° C. of about 260 mm²/sec;

FIG. 3 shows the increase in the apparent dynamic viscosity of aninventive high-temperature oil based on two components from example 1compared with a known oil based on three components from comparativeexample 1 at a kinematic base oil viscosity at 40° C. of about 260mm²/sec;

FIG. 4 shows the friction values as a function of temperature at a loadof 250 N for an inventive high-temperature oil based on two componentsfrom example 2 compared with a known oil based on three components fromcomparative example 2;

FIG. 5 shows the vaporization losses for an inventive high-temperatureoil based on two components from example 2 compared with a known oilbased on three components from comparative example 2 at a kinematic baseoil viscosity at 40° C. of about 100 mm²/sec;

FIG. 6 shows the increase in the apparent viscosity of an inventivehigh-temperature oil based on two components from example 2 comparedwith a known oil based on three components from comparative example 2 ata kinematic base oil viscosity at 40° C. of about 100 mm²/sec;

FIG. 7 shows the friction values as a function of temperature at a loadof 250 N for an inventive high-temperature oil based on two componentsfrom example 3 compared with a known oil based on three components fromcomparative example 3;

FIG. 8 shows the vaporization losses for an inventive high-temperatureoil based on two components from example 3 compared with a known oilbased on three components from comparative example 3 at a kinematic baseoil viscosity at 40° C. of about 680 mm²/sec;

FIG. 9 shows the increase in the apparent dynamic viscosity of aninventive high-temperature oil based on two components from example 3compared with a known oil based on three components from comparativeexample 3 at a kinematic base oil viscosity at 40° C. of about 680mm²/sec;

FIG. 10 shows the vaporization losses for an inventive high-temperatureoil based on two components with an ionic liquid from example 4 comparedwith comparative example 4, which corresponds to example 1 at akinematic base oil viscosity of about 260 mm²/sec;

FIG. 11 shows the increase in the apparent dynamic viscosity of aninventive high-temperature oil based on two components with an ionicliquid from example 4 compared with comparative example 4, whichcorresponds to example 1 at a kinematic base oil viscosity of about 260mm²/sec;

FIG. 12 shows the experimental setup for the high-performance chain testbed.

The invention is now illustrated in detail by the examples which follow.

EXAMPLE 1

Production of an inventive two-component high-temperature oil

Composition of the high-temperature oil:

63.4% by weight of aromatic trimellitic ester

30.0% by weight of fully hydrogenated polyisobutylene

3.5% by weight of antiwear agent

3.0% by weight of antioxidant

0.1% by weight of anticorrosive

As the aromatic ester, trimellitic ester is initially charged in astirred tank. At 100° C., the polyisobutylene is added while stirring.Subsequently, the mixture is stirred for one 1 hour in order to obtain ahomogeneous mixture. The antiwear agent and the antioxidant are added tothe tank at 60° C. while stirring. After about 1 hour, the finished oilcan be dispensed into the containers provided.

COMPARATIVE EXAMPLE 1

Production of a known three-component high-temperature oil

Composition of the high-temperature oil:

47.4% by weight of aromatic trimellitic ester

16.0% by weight of polyisobutylene

30.0% by weight of synthetic hydrocarbon

3.5% by weight of antiwear agent

3.0% by weight of antioxidant

0.1% by weight of anticorrosive

As the aromatic ester, trimellitic ester is initially charged in astirred tank together with the poly-α-olefin as the synthetichydrocarbon. At 100° C., the polyisobutylene is added while stirring.Subsequently, the mixture is stirred for 1 hour in order to obtain ahomogeneous mixture. The antiwear agent and the antioxidant are added tothe tank at 60° C. while stirring. After about 1 hour, the finished oilcan be dispensed into the containers provided.

The advantages of the inventive high-temperature oil are shownhereinafter.

The base data for the oil according to example 1 and comparative example1 are shown in table 1.

TABLE 1 Comparative Example 1 example 1 Appearance clear clear Kinematicviscosity 271 mm²/sec 275 mm²/sec 40° C. Kinematic viscosity 24 mm²/sec25 mm²/sec 100° C. Flashpoint >250° C. >250° C. Pour point −30° C. −30°C.

1.1. Thermal Stability Studies

Studies were conducted with regard to vaporization and viscosity underthermal stress on a starting weight of 5 g in an aluminum pan at 230° C.For this purpose, the oils according to example 1 and comparativeexample 1 were compared with one another.

TABLE 2 Comparative Example 1 example 1 Vaporization loss 16% 30% after24 h/230° C. Vaporization loss 25% 49% after 48 h/230° C. Vaporizationloss 35% 62% after 72 h/230° C. Increase in  970 mPas 1300 mPas apparentdynamic viscosity after 24 h/230° C. Increase in 1400 mPas 4400 mPasapparent dynamic viscosity after 48 h/230° C. Increase in 3200 mPas 41000 mPas apparent dynamic viscosity after 72 h/230° C.

The above results show that the use of fully hydrogenatedpolyisobutylene in a two-component high-temperature oil can distinctlyreduce the rise in viscosity and in the vaporization loss compared tothe known three-component oil. These results are also shown in the formof graphs in FIGS. 2 and 3.

1.2. Comparison of the Friction Values

The oils produced in example 1 and comparative example 1 were used fordetermination of the friction values. For this purpose, an oscillatingfrictional wear test (SRV) was conducted based on DIN 51834, ball/disktest condition, load 250 N, 50° C. to 250° C., stroke 1 mm, 50 Hz, 165min. The results are shown in table 3.

TABLE 3 Comparative Example 1 example 1 SRV TST 250N point Frictionnumber Friction number 50 to 120° C.   0.104 0.109 to 140° C. 0.1050.109 to 160° C. 0.102 0.118 to 180° C. 0.096 0.128 to 200° C. 0.0900.138 to 210° C. 0.087 0.145 to 220° C. 0.087 0.151 to 230° C. 0.0910.159 to 240° C. 0.102 0.166 to 250° C. 0.110 0.169

These results, which are also shown in FIG. 1, show the positive effectof the high-temperature oil based on two components on the frictionnumber compared to the three-component system.

1.3. Residue Characteristics After Complete Vaporization of the Oil at250° C.

The formation of residues and the behavior of the residues with regardto solubility were studied.

The oil to be tested is weighed to 5 g onto a steel sheet which has beenbent to size and cleaned with solvent beforehand, and then vaporized offat 250° C. in an air circulation drying cabinet for min. 72 h. Thesquare sheet is bent manually on all four sides, so as to give a dishshape.

After cooling, the results of the re-weighing are documented.

Important features for this test are the determination of thedissolvability of the residue surface with fresh oil and the amount ofresidue formed. For this purpose, a drop of the fresh oil is applied tothe residue and rubbed in gently by means of a rounded glass rod withcircular movements.

The results show that the inventive high-temperature oil forms a lowerlevel of residue at 4.8% than the known oil, which has a residue of6.0%. The residue formed from the inventive high-temperature oil hasvery good surface dissolvability, which means that these residues areeasy to dissolve with fresh oil. In contrast, the residue of the knownoil has much poorer surface redissolvability with fresh oil.

1.4. High-Performance Chain Test Bed

FIG. 12 shows the high-performance chain test bed, which works under thefollowing test conditions:

Temperature: 220° C.

Speed: 2 m/sec

Load: 2600 N

Run time after 0.1% chain lengthening 22 hours for example 1, and 17hours for comparative example 1.

Before the test, the chain is immersed into the lubricant oil to betested. After the immersion, the chain is suspended, such that theexcess lubricant can drip off. Subsequently, the chain is installed intothe chain test bed (see FIG. 10) and the test is started under theconditions defined. It is possible to vary the temperature, the speedand the load.

The run time is fixed at a chain lengthening of 0.1%. The lengthening ofthe chain arises through wear at the chain members during the test run.

EXAMPLE 2

Composition of the inventive high-temperature oil:

82% by weight of aromatic trimellitic ester

12.7% by weight of fully hydrogenated polyisobutylene

0.3% by weight of antiwear agent

4.5% by weight of antioxidant

0.5% by weight of anticorrosive

The production is effected as described in example 1.

COMPARATIVE EXAMPLE 2

Composition of the three-component high-temperature oil:

55.7% by weight of aromatic trimellitic ester

7% by weight of polyisobutylene

33.20% by weight of synthetic hydrocarbon

0.30% by weight of antiwear agent

3.7% by weight of antioxidant

0.10% by weight of anticorrosive

The production is effected as described in comparative example 1.

The advantages of the inventive high-temperature oil are shownhereinafter.

The base data for the oil according to example 2 and comparative example2 are shown in table 4.

TABLE 4 Viscosity at 40° C., Comparative 100 mm²/sec Example 2 example 2Appearance clear clear Kinematic viscosity 120.0 mm²/sec 107.0 mm²/sec40° C. Kinematic viscosity 14 mm²/sec 13.5 mm²/sec 100° C.Flashpoint >250° C. >250° C. Pour point −20° C. −30° C.

2.1. Thermal Stability Studies

Studies were conducted with regard to the vaporization and viscosityunder thermal stress on a starting weight of 5 g in an aluminum pan at230° C. For this purpose, the oils according to example 2 andcomparative example 2 were compared with one another.

TABLE 5 Comparative Example 2 example 2 Vaporization loss 18% 36% after24 h/230° C. Vaporization loss 37% 57% after 48 h/230° C. Vaporizationloss 52% 71% after 72 h/230° C. Increase in  340 mPas 430 mPas apparentdynamic viscosity after 24 h/230° C. Increase in 1250 mPas 200 mPasapparent dynamic viscosity after 48 h/230° C. Increase in 4700 mPas 23000 mPas apparent dynamic viscosity after 72 h/230° C.

The above results show that the use of fully hydrogenatedpolyisobutylene in a two-component high-temperature oil can distinctlyreduce the rise in viscosity and in the vaporization loss compared tothe known three-component oil. These results are also shown as graphs inFIGS. 5 and 6.

2.2. Comparison of the Friction Values

The oils produced in example 2 and comparative example 2 were used todetermine the friction values. For this purpose, an oscillatingfrictional wear test (SRV) was conducted based on DIN 51834, ball/disktest condition, load 250 N, 50° C. to 250° C., stroke 1 mm, 50 Hz, 165min.

The results are shown in table 6.

TABLE 6 Comparative Example 2 example 2 SRV TST 250N point Frictionnumber Friction number 50 to 120° C.   0.097 0.105 to 140° C. 0.0930.112 to 160° C. 0.122 0.129 to 180° C. 0.133 0.136 to 200° C. 0.1380.143 to 210° C. 0.139 0.157 to 220° C. 0.136 0.175 to 230° C. 0.1380.186 to 240° C. 0.136 0.196 to 250° C. 0.136 0.205

These results, which are also shown in FIG. 4, show the positive effectof the high-temperature oil based on two components on the frictionnumber compared to the three-component system.

2.3. Residue Characteristics after Complete Vaporization of the Oil at250° C.

The formation of residues and the behavior of the residues in terms ofsolubility were studied. The method is described in example 1.

Both the inventive high-temperature oil and the known oil had a residueof 3.0%; the residue formed from the inventive high-temperature oil hadvery good surface dissolvability, which means that these residues can bedissolved easily with fresh oil. In contrast, the residue of the knownoil has much poorer surface redissolvability with fresh oil.

2.4. High-Performance Chain Test Bed

The test on the high-performance chain test bed was conducted at 220°C., a speed of 2.0 m/sec and a load of 2600 N. The run time after chainlengthening 0.1% is 19 h for example 2, and that for comparative example2 is 17 h.

The test was conducted as described in example 1.

EXAMPLE 3

Composition of the Inventive High-Temperature Oil:

45.4% by weight of aromatic trimellitic ester

48.00% by weight of fully hydrogenated polyisobutylene

2.5% by weight of antiwear agent

3.0% by weight of antioxidant

0.1% by weight of anticorrosive

The production was effected as described in example 1.

COMPARATIVE EXAMPLE 3

Composition of the Three-Component High-Temperature Oil:

47.0% by weight of aromatic trimellitic ester

17.4% by weight of polyisobutylene

29.0% by weight of synthetic hydrocarbon

3.5% by weight of antiwear agent

3.0% by weight of antioxidant

0.10% by weight of anticorrosive

The production was effected as described in comparative example 1.

The advantages of the inventive high-temperature oil are shownhereinafter.

The base data for the oil according to example 3 and comparative example3 are shown in table 7.

TABLE 7 Viscosity at 40° C., Comparative 680 mm²/sec Example 3 example 3Appearance clear clear Kinematic viscosity 690 mm²/sec 690 mm²/sec 40°C. Kinematic viscosity 24 mm²/sec 47 mm²/sec 100° C. Flashpoint >250°C. >250° C. Pour point −30° C. −30° C.

3.1. Thermal Stability Studies

Studies were conducted with regard to vaporization and viscosity underthermal stress on a starting weight of 5 g in an aluminum pan at 230° C.For this purpose, the oils according to example 3 and comparativeexample 3 were compared with one another.

TABLE 8 Comparative Example 3 example 3 Vaporization loss 18% 20% after24 h/230° C. Vaporization loss 28% 38% after 48 h/230° C. Vaporizationloss 37% 53% after 72 h/230° C. Increase in 3400 mPas 2800 mPas apparentdynamic viscosity after 24 h/230° C. Increase in 6000 mPas 13 250 mPasapparent dynamic viscosity after 48 h/230° C. Increase in 12 700 mPas 47000 mPas apparent dynamic viscosity after 72 h/230° C.

The above results show that the use of fully hydrogenatedpolyisobutylene in a two-component high-temperature oil can reduce therise in viscosity and in the vaporization loss compared to the knownthree-component oil. These results are also shown as graphs in FIGS. 8and 9.

3.2. Comparison of the Friction Values

The oils produced in example 3 and comparative example 3 were used todetermine the friction values. For this purpose, an oscillatingfrictional wear test (SRV) was conducted based on DIN 51834, ball/disktest condition, load 250 N, 50° C. to 250° C., stroke 1 mm, 50 Hz, 165min.

The results are shown in table 9.

TABLE 9 Comparative Example 3 example 3 SRV TST 250N point Frictionnumber Friction number 50 to 120° C.   0.119 0.118 to 140° C. 0.1160.115 to 160° C. 0.119 0.114 to 180° C. 0.115 0.110 to 200° C. 0.1050.108 to 210° C. 0.098 0.105 to 220° C. 0.096 0.102 to 230° C. 0.0990.102 to 240° C. 0.112 0.089 to 250° C. 0.126 0.086

These results, which are also shown in FIG. 7, show the positive effectof the high-temperature oil based on two components on the frictionnumber compared to the three-component system.

3.3. Residue Characteristics After Complete Vaporization of the Oil at250° C.

The formation of residues and the behavior of the residues in terms ofsolubility were studied. The test was conducted as described in example1.

The results show that the inventive high-temperature oil forms a lowerlevel of residues at 4.8% than the known oil, which has a residue of11.8%. The residue formed from the inventive high-temperature oil hasvery good surface dissolvability, which means that these residues can bedissolved easily with fresh oil. In contrast, the residue of the knownoil has much poorer surface redissolvability with fresh oil.

3.4. High-Performance Chain Test Bed

The test on the high-performance chain test bed was conducted at 220°C., a speed of 2.0 m/sec and a load of 2600 N. The run time after chainlengthening 0.1% was 17 h for example 3 and 15 h for comparative example3. The test was conducted as described in example 1.

EXAMPLE 4

Composition of the Inventive High-Temperature Oil:

62.90% by weight of aromatic trimellitic ester

30.00% by weight of fully hydrogenated polyisobutylene

3.5% by weight of antiwear agent

3.0% by weight of antioxidant

0.1% by weight of anticorrosive

0.50% by weight of ionic liquid

The production was effected as described in example 1.

The ionic liquid used was HDP imide (=trihexyl(tetradey-phosphoniumbis(trifluoromethylsulfonyl)imide).

COMPARATIVE EXAMPLE 4 Corresponds to Example 1

Composition of the inventive high-temperature oil:

63.40% by weight of aromatic trimellitic ester

30.00% by weight of fully hydrogenated polyisobutylene

3.5% by weight of antiwear agent

3.0% by weight of antioxidant

0.1% by weight of anticorrosive

The production was effected as described in example 1.

The base data for the oil according to example 4 and comparative example4 are shown in table 10.

TABLE 10 Viscosity at 40° C., Comparative example 4 200 mm²/sec Example4 (corresponds to ex. 1) Appearance clear clear Kinematic viscosity270.0 mm²/sec 271.0 mm²/sec 40° C. Kinematic viscosity 24 mm²/sec 25mm²/sec 100° C. Flashpoint >250° C. >250° C. Pour point −30° C. −30° C.

4.1. Thermal Stability Studies

Studies were conducted with regard to the vaporization and viscosityunder thermal stress on a starting weight of 5 g in a closed aluminumpan at 250° C. The vaporization loss after 72 h/250° C. was 19%. Theincrease in apparent dynamic viscosity in mPas after 72 h/250° C. was2300 mPas.

TABLE 11 Comparative example 4 Example 4 Corresponds to example 1Vaporization loss 19% 46% after 72 h/250° C. Increase in 2300 mPas 27000 mPas apparent dynamic viscosity after 72 h/250° C.

The above results show that the use of HDP imide can once againsignificantly improve the thermal stability of a two-component system.These results are also shown as graphs in FIGS. 10 and 11.

EXAMPLE 5

Composition of the Inventive High-Temperature Oil:

63.5% phloroglucinol tridecanoate

30.0% fully hydrogenated polyisobutylene

3.5% antiwear agent

3.0% antioxidant

0.1% by weight of anticorrosive

The production was effected as described in example 1.

It was also possible to obtain the results described in detail abovewith the high-temperature oil based on a derivative of phloroglucinol.

The above experimental results show that the inventive high-temperatureoil in all studies conducted gave much better values than in the case ofthe known high-temperature oils.

In summary, it can be stated that the inventive two-component system hasmuch higher performance with regard to thermal stability and residueformation or residue characteristics. The enormous rise in thermalstability is manifested particularly in a distinct rise in lubricationcharacteristics. The relubrication intervals were extended and an energysaving of up to a 30% power saving was achieved.

1. A high-temperature oil for lubrication of chains, chain rollers andbelts of continuous presses, comprising 40 to 91.9% by weight of anaromatic ester of the general formula (I)

where R1 is a linear or branched alkyl group having 6 to 16 carbon atomsand n is an integer of 3 to 4, or 40 to 91.9% by weight of a compound ofthe general formula (II)

where R is a linear or branched alkyl group having a chain length of 8to 16 carbon atoms and n is equal to 3, and 5 to 50% by weight of ahydrogenated polyisobutylene, of a fully hydrogenated polyisobutylene orof a mixture of a fully hydrogenated and a hydrogenated polyisobutylene.2. The high-temperature oil as claimed in claim 1, further comprising0.1 to 6% by weight of an antioxidant.
 3. The high-temperature oil asclaimed in claim 1, further comprising 1 to 4% by weight of an antiwearagent.
 4. The high-temperature oil as claimed in claim 1, furthercomprising 0.1 to 0.5% by weight of an anticorrosive.
 5. Thehigh-temperature oil as claimed in claim 1, further comprising 0 to 2%by weight of an ionic liquid.
 6. The high-temperature oil as claimed inclaim 1, wherein the ester compound of the general formula (I) isselected from the group consisting of esters of trimellitic acid,pyromellitic acid, trimesic acid or of a mixture thereof.
 7. Thehigh-temperature oil as claimed claim 1, wherein the compound of thegeneral formula (II) is a derivative of phloroglucinol(benzene-1,3,5-triol).
 8. The high-temperature oil as claimed in claim7, in which the derivative of phloroglucinol is phloroglucinoltrioctanoate, phloroglucinol tridecanoate or phloroglucinoltridodecanoate.
 9. The high-temperature oil as claimed in claim 2,wherein the antioxidant bears sulfur and/or nitrogen and/or phosphorusin the molecule, and is selected from the group consisting of aromaticaminic antioxidants such as alkylated phenyl-alpha-naphthylamine,dialkyldiphenylamine, sterically hindered phenols such asbutylhydroxytoluene (BHT), phenolic antioxidants having thioethergroups, zinc dialkyldithiophosphates or molybdenumdialkyldithiophosphates or tungsten dialkyldithiophosphates, andphosphites.
 10. The high-temperature oil as claimed in claim 3, whereinthe antiwear agent is selected from the group consisting of antiwearadditives based on diphenyl cresyl phosphate, amine-neutralizedphosphates, alkylated and nonalkylated triaryl phosphates, alkylated andnonalkylated triaryl thiophosphates, zinc dialkyldithiophosphates ormolybdenum dialkyldithiophosphates or tungsten dialkyldithiophosphates,carbamates, thiocarbamates, zinc dithiocarbamates or molybdenumdithiocarbamates or tungsten dithiocarbamates, dimercaptothiadiazole,calcium sulfonates and benzotriazole derivatives.
 11. Thehigh-temperature oil as claimed in claim 4, wherein the anticorrosive isselected from the group consisting of additives based on overbasedcalcium sulfonates, amine-neutralized phosphates, alkylated calciumnaphthalenesulfonates, oxazoline derivatives, imidazole derivatives,succinic monoesters, N-alkylated benzotriazoles.
 12. Thehigh-temperature oil as claimed in claim 5, wherein the ionic liquid isselected from the group consisting of tetraalkylammoniumbis(trifluoromethylsulfonyl)imides and tetraalkylphosphoniumbis(trifluoromethylsulfonyl)imides, for exampletrihexyl(tetradecyl)phosphonium bis(trifluoromethylsulfonyl)imide(HPDimide) and methyltrioctylammonium bis(trifluoromethylsulfonyl)imide(Moimide), and tetraalkylammonium tris(perfluoroethyl)trifluorophosphateand tetraalkylphosphonium tris(perfluoroethyl)trifluorophosphate,especially tetrabutylphosphonium tris(perfluoroethyl)trifluorophosphate(BuPPFET), trihexyl(tetradecyl) tris(perfluoroethyl)trifluorophosphate(HDPPFET), pyrrolidinium tris(perfluoroethyl)trifluorophosphates,tetraalkylammonium, tetraalkylphosphonium perfluorobutanesulfonates,trihexyl(tetradecyl)phosphonium perfluorobutanesulfonate (HDPnonaflate).13. The use of the high-temperature oil as claimed in any of claim 1 forindustrial chain lubrication in conveying systems, painting lines, thetextile industry, the insulating materials industry, the glass industry,or for belt lubrication in continuous wood pressing plants.
 14. Thehigh-temperature oil as claimed in claim 2, further comprising 1 to 4%by weight of an antiwear agent.
 15. The high-temperature oil as claimedin claim 2, further comprising 0.1 to 0.5% by weight of ananticorrosive.
 16. The high-temperature oil as claimed in claim 3,further comprising 0.1 to 0.5% by weight of an anticorrosive.
 17. Thehigh-temperature oil as claimed in claim 2, further comprising 0 to 2%by weight of an ionic liquid.
 18. The high-temperature oil as claimed inclaim 3, further comprising 0 to 2% by weight of an ionic liquid. 19.The high-temperature oil as claimed in claim 4, further comprising 0 to2% by weight of an ionic liquid.